Optical fibers are increasingly used for data communications. Optical fibers have several advantages over conventional electrical wires. For example, optical fibers are more resistant to electro-magnetic interference and have higher data transmission rates. Communications through optical fibers are also more secure than by electrical wire since the signal does not create an electromagnetic field as an electrical signal does. Also, data may be transmitted over greater distances without suffering as much signal loss as that encountered in copper wires.
Typically, optical signals are converted to electrical signals when they reach their destination so that the data contained in the optical signals can be processed by conventional electronic devices. Similarly, data that is in the form of electrical signals must be converted to optical signals before being transmitted through optical fibers. Typically, such conversion is done by modules that are connected to both a host system and to one or more optical fibers.
Connection to a host system must be mechanically secure so that the module is not unintentionally disconnected from the host, for example when the optical fiber is moved. It must also be possible to remove the module when required without affecting neighboring modules. This is normally achieved with a latching mechanism that holds the module in place within the host system until the latching mechanism is de-latched prior to removal of the module.
Standards exist for the design of transceiver modules of this kind. One such standard is the Small Formfactor Pluggable (SFP) Multi Sourcing Agreement (MSA). This agreement requires that the module conform to certain specifications of size and shape, and also governs the electrical interface used. The SFPMSA standard also requires modules to be hot-pluggable, that is, they must be capable of being inserted or removed from the host system while the power is turned on. To facilitate removal, it is usually necessary to allow a space between modules to permit access to a latching mechanism located on the sides of the module. This prevents such modules from being used in systems with high port density unless an extraction tool is employed. Extraction tools are undesirable for a number of reasons including convenience, cost and compatibility with other systems.
Therefore, there is a need for a module that is capable of being securely held in a host system, capable of being withdrawn from the host system when needed, is compatible with a high port density system and conforms to the SFP standard. In addition such a module should require no special extraction tool and should allow extraction without affecting neighboring modules. Specifically, a latching mechanism is needed that allows high-density arrangement of hot-pluggable modules without requiring an extraction tool.